1. Field
The present invention relates to a charge pump and voltage regulator system, and more particularly to a charge pump and voltage regulator system for multilevel memory cell systems.
2. Description of Related Information
A conventional mixed mode integrated circuit system frequently uses different voltage supplies. Analog signal processing, such as amplification, comparison, and pulse generation, may be performed at high voltage. A flash memory applies an erase signal, a programming signal, and a read signal to memory cells. The erase signal, the programming signal, and the read signal have voltage levels greater than a supply voltage. Also in multilevel volatile memories, the variation of the voltage level of the signal falls in a smaller range for the multibit signals stored in the memory cells. A charge pump and a voltage regulator may be used to generate the erase signal, the programming signal, and the read signal.